System of electrical distribution.



R. PALMER. V SYSTEM OF ELECTRICAL DISTRIBUTION.

APPLICATION FILED OCT. 30, 1909.

991,080. Patented May 2, 1911.

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TlNTTEU STATES PATENT RODERICK M. PALMER, OF CAMBRIDGE, MASSACHUSETTS,ASSIGNOR TO JAMES H. CARY, OF BOSTON, MASSACHUSETTS.

SYSTEM OF ELECTRICAL DISTRIBUTION.

To all whom it may concern:

Be it known that I, RODERICK M. PALMER, a citizen of the United States,residing in Cambridge, county of Middlesex, and State of Massachusetts,have invented an Improvement in Systems of Electrical Distribution, ofwhich the following description, in connection with the accompanyingdrawings, is a specification, like letters on the drawings representinglike parts.

This invention relates to a system of electrical distribution in which acurrent of relatively high voltage may be used with safety withtranslating devices operated by a current of relatively low voltage, andis an improvement upon the system shown and described in U. S. PatentNo. 807 ,960 granted to me December 19, 1905.

The present invention has for its object to provide a system of theclass described, in which waste of current upon the closed primary highvoltage circuit is avoided, and further has for its object to render thesystem less sensitive and more reliable as will be described.

The invention also has for its object to provide against the highvoltage current accidentally getting to the low voltage circuit.

These and other features of this invention will be pointed out in theclaims at the end of this specification.

The drawing is a diagrammatic view of a system embodying this invention.

Referring to the drawing a, 5, represent the line wires of a circuit ofrelatively high voltage, such, for instance, as an incandescent lampcircuit having a current of 110 volts. The circuit of relatively lowvoltage is represented by the line wires 0, (Z, which include atranslating device, hereinshown as a bell f, which is responsive to acurrent of low voltage, as, for instance, 10 volts, and a service switch9, which is normally open.

The high voltage circuit a, Z), includes a plurality of resistances,hereinshown as four in number and marked 10, 12, 13, 14:, which arelocated on a board 15, which is designed to be located in the basementof the building or other structure in which the low voltage circuit 0,(Z is used. The board 15 is pro vided with terminals 16, 17, 18, 19, 20and 21, with which the resistances are connected as represented in thedrawing.

The high voltage circuit between the ter minals 19, 20, includes anelectromagnet or Specification of Letters Patent.

Application filed October 30, 1909.

Patented May 2, 1911.

Serial No. 525,449.

relay 25 having a winding of fine wire 26 and a winding of coarse wire27 for a purpose as will be described. The fine winding 26 has itsopposite ends connected by wires 28, 29, with the terminals 19, 20respectively. The coarse winding 27 has its ends connected by wires 30,31, with the terminal 21 and with a terminal 32 with which the wire (Zof the low voltage circuit is connected. It will thus be seen that bothwindings 26, 27, of the relay or electromagnet 25 are included in thehigh voltage circuit in series relation, which circuit may be traced asfollows. By the outside line a to the terminal post 16, thence by theresistances 10, 12, 13 to terminal post 19, thence by wire 28, finewinding 26, wire 29, to terminal post 20, thence by resistance 14-,terminal post 21, wire 30, coarse winding 27, wire 31, terminal 32 andwire Z). The resistances thus included in the primary high voltagecircuit reduce the amperage of the high voltage current, so that whenthe low voltage circuit is closed at the service switch} a current oflow voltage and low amperage flows over the same, and by providing therelay 25 with the double winding of fine and coarse wire, and includingboth of these windings in the high voltage circuit, the amperage of thecurrent flowing continuously through the primary circuit while theservice switch 9 is open is reduced to a minimum, for instance, 1 1O ofan ampere, and as a result waste of current is avoided. The current oflow amperage, namely, 1/410 of an ampere is sufiicient to maintain therelay 25 energized so as to attract its armature 40 and thereby completethe low voltage circuit except at the service switch, but is notsufficient to operate the bell or other translating device in the lowvoltage circuit. The coarse winding 27 of the relay 25 serves to carrythe heavy current of say for instance 10 amperes, which flows over thelow voltage circuit when the service switch 9 is closed.

The circuit just described may be designated the initial low voltagecircuit and includes a relay having a double winding comprising awinding 51 of fine wire, and a winding 52 of coarse wire, which are inseries relation, one end of the fine wire winding 51 being connected bythe wire 53 with the terminal post 18, and the other end of said windingbeing connected by wire 54 with one end of the coarse winding 52, theother end of which is connected by wire 55 to a terminal 56 with whichcooperates the armature s 0 of the relay 25, said armature cooperatingas shown in the drawing with a terminal 57, which is connected by thewire 58 with the terminal post 59 to which the wire 0 of the low voltagecircuit is connected. The initial low voltage circuit may be traced asfollows z-line wire a to terminal post 16, thence through the resistances 10, 12, to terminal post 18, thence by wire 53, fine winding 51 ofrelay 50, wire 51, coarse winding 52 of said relay, wire 55, terminal56, armature 41.0, terminal 57, wire 58, post 59, wire 0, switch g, bellf, wire (1, post 32, and wire Z). The relay 50 is thus energized andattracts its armature 60,which cooperates with the terminals 61, 62, theterminal 61 being connected by wire 63 with wire 54, and the terminal 62being connected by wire 65 with post- 17, thereby establishing what maybe termed the low voltage working circuit, which may be traced asfollows:line wire a to post 16, resistance 10 to post 17, thence by wire65, terminal 62, armature 60, terminal 61, wires 63, 54-, coarse winding52, wire 55, terminal 56, armature 10, terminal 57, wire 58, post 59,wire 0, switch g, bell f, wire (Z, post 32 and line wire Z), Thearmature 60 in its attracted position also completes ashunt circuitthrough the coarse winding 27 ot' the relay 25, and for this purpose thearmature 60 is joined by a flexible connection with a wire 71, which isconnected with the wire 29. This shunt circuit may be traced as fol lows:line wire a, post 16, resistance 10, post 17, wire 65, terminal 62,armature 60, flexible connection 70, wires 71, 29, post 20, resistance 11-, post 21, wire 30, winding 27, wire 31, post 32 and line wire 6. Theshunt circuit just described, short circuits the resistances 12 and 13,thereby controlling both the voltage and amperage to the rated ordesired capacity of the apparatus, that is, the exclusion of the finewindings 51, 26 of the relays 50, 25, respectively, and the resistances12, 13, increases the amperage of the current flowing over the lowvoltage working circuit while maintaining the volt-- age of the workingcurrent low, say, for instance, 1.0 volts. The danger of sparkingbetween the armature 60 and its terminals 61, 62, when the armaturedrops away, is prevented by a condenser placed across the wires 65, 71.

From the above description, it will be seen that under normal conditionswith the switch. 9 open, both the fine and coarse windings 26, 27 of therelay are in series with each other and with the main resistances on theboard 15 and form part of the total re sistance of the primary or highvoltage circuit, which arrangement serves as a safety device for theapparatus, for if any portion of this primary circuit should becomeinoperative from any cause, the armature 10 would drop and open thesecondary or low voltage circuit. The fine winding 26 on the relay 25enables the said relay to be energized with a current of very smallamperage, as, for instance, 1/ 10 of an ampere. It will thus be seenthat waste of current flowing through the apparatus with the serviceswitch 9 open, is reduced to a minimum, and the cost of using the highvoltage current for operating bells or other translating devices in thelow voltage circuit is reduced by this arrangement.

The fine winding 51 on the relay 50 enables the armature 60 to have awide range of movement, as the fine winding can be given any desirednumber 017' turns around the cores of the relay to cause the pull of therelay to be increased to such extent as to respond to a weak current,that is, a current of relatively low voltage and amperage, therebyavoiding the necessity of finely a djusting the arn'iature and alsoavoiding de t'ects in the system from this source.

It will be observed that the armature 60 is a current carrying armaturewhich. forms two shunt circuits, each in series with the resistance 10.One of said shunt circuits is the low voltage circuit which includes thebell f, and may be traced as follows. ire a, terminal post 16,resistance 10, terminal post 17, wire 65, terminal 62, armature 60,terminal 61, wire 63, wire 5-1, winding 52, wire 55, terminal 56,armature 10, terminal 57, wire 58, terminal post 59, wire 0, switch g,bell 7', wire (Z, terminal post 32 and wire 6. The full voltage of thehigh voltage current is prevented from flowing through the aforesaidcircuit by resistance let which is included in the other shunt circuit.The shunt circuit which includes resistance 11- may be traced over theaforesaid circuit as far as the armature 60 where the current isdivided. From the armature 60 the high voltage current flows over wires7 0 and 71, wire 20, terminal post 20, resistance 14., terminal post 21,wire 30, coarse winding 27, wire 31, terminal post 32 and wire 7). Theobject of providing the armature 60 to establish shunt circuits is toprevent a current of an excessive voltage from flowing through the lowvoltage shunt which in cludes the bell f.

The earth connection 81, 82, with the binding post 82 may or may not beused, according to the condition of the high voltage circuit with whichthe apparatus is used.

Claims.

1. In a system of the class described, in combination, a closed circuitof relatively high voltage, a second circuit containing a translatingdevice responsive to a current of relatively low voltage, resistance inthe closed high voltage circuit, a circuit controller in the low voltagecircuit, a relay having a fine and a coarse winding in series with eachother and with the resistance in the closed high voltage circuit andgoverning said circuit controller, a relay in the low voltage circuithaving a fine and a coarse winding in series with each other and with aportion of the resistance in the high voltage circuit, and a circuitcontroller governed by the relay in the low voltage circuit and actingto exclude from the low voltage circuit portions of the resistance inthe high voltage circuit, the fine winding of the relay in the lowvoltage circuit and the fine winding of the relay in the high voltagecircuit, substantially as described.

2. In a system of the class described, in combination, a closed circuitof relatively high voltage, a second circuit containing a translatingdevice responsive to a current of relatively low voltage, resistance inthe closed high voltage circuit, a circuit controller in the low voltagecircuit, an electromagnet in said high voltage circuit governing saidcircuit controller, an electromagnet in the low voltage circuit having afine and a coarse winding in series with each other and with a portionof the resistance in the high voltage circuit, and a circuit controllergoverned by the electromagnet in the low voltage circuit and acting toexclude from the low voltage circuit a portion of the resistance in thehigh voltage circuit and the fine winding of the relay in the lowvoltage circuit, substantially as described.

3. In a system of the class described, in combination, a closed circuitof relatively high voltage, a second circuit containing a translatingdevice responsive to a current of relatively low voltage, resistance inthe closed high voltage circuit, a circuit controller in the low voltagecircuit, an electromagnet in said high voltage circuit governing saidcircuit controller, an electromagnet in the low voltage circuitconnected with a portion of the resistance in the high voltage circuit,an armature for said electromagnet adapted to close the low voltagecircuit through a portion of the resistance of the high voltage circuit,and a terminal with which said armature cooperates, said terminal beingconnected with a portion of the resistance of the high voltage circuit.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses.

RODERICK M. PALMER.

l Vitnesses:

J AS. H CHURoI-IILL, J. MURPHY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

